Adult and aged female rhesus macaques and squirrel monkeys were injected with the neurotoxin DSP4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine) or vehicle, with repeat injections after three and six months. At nine months post-initial treatment, brain samples were collected for measurement of catecholamines, amyloid precursor protein, soluble amyloid-Beta peptides (1-40 and 1-42) and Beta-site APP cleaving enzyme-1. Immunohistochemistry was used to assess amyloid distribution (6E10) and localization of dopamine Beta-hydroxylase in locus coeruleus sections. The in vivo portion of this study and all tissue analyses have been completed. The manuscript is nearing completion.